The CyberData outdoor intercom. As its an IP device it runs over the Ethernet. This image is the keypad version. You can also purchase as just a call button option. Works great with hosted voip platforms.
This page is an overview of the gate ip intercom. The device is also used on barriers. IP Phones and mobile phones trigger the gate/barrier. This is a SIP based device that connects to ip phone systems. Approved by Cisco, Avaya, Broadsoft and many more.